Plyometric Jump Box

ABSTRACT

A plyometric jump box includes a foam outer box having six sides. Each side includes a 4 inch thick cross-linked polyethylene closed cell foam sheet material having a density of between 4 lbs./ft.3 and 6 lbs./ft.3. The box defines a cavity therein. A support structure is disposed inside of the cavity and is coupled to each of the sides so as to provide support to each of the sides.

BACKGROUND OF THE INVENTION 1. Field of the Invention

The present invention relates to athletic training devices and, more specifically, to an athletic jump training device.

2. Description of the Related Art

Plyometric exercises cause muscles to exert maximum force quickly. Such exercises are used to improve the explosiveness of athletes in training. Fitness enthusiasts also use plyometric exercises to develop strength and endurance.

One type of plyometric exercise involves jump training, in which the person in training jumps from one surface to a higher surface. The higher surface is usually the top surface of an elevated platform or a box, which is often referred to as a “plyometric jump box” or a “plyobox.”

Typical jump boxes are made of wood. Wooden jump boxes can be inexpensive and provide good support for the person in training. However, missing the box while jumping can result in the jumper sustaining injuries, including injuries to the shins and knees.

One type of jump box is made with a dense foam core surrounded by a soft foam shell, which is surrounded by a vinyl pouch. This type of jump box is more costly than typical wooden jump boxes and the vinyl surface can result in the jump box slipping when placed on certain types of flooring surfaces. Such slipping can also result in injuries.

Therefore, there is a need for a plyometric jump box that has a resilient surface, that is economical and that is unlikely to slip on most surfaces.

SUMMARY OF THE INVENTION

The disadvantages of the prior art are overcome by the present invention which, in one aspect, is a plyometric jump box that includes a foam outer box having six sides. Each side includes a 4 inch thick cross-linked polyethylene closed cell foam sheet material having a density of between 4 lbs./ft.³ and 6 lbs./ft.³. The box defines a cavity therein. A support structure is disposed inside of the cavity and is coupled to each of the sides so as to provide support to each of the sides.

In another aspect, the invention is a jump box that includes a foam outer box having six sides. Each side includes a 4 inch thick cross-linked polyethylene closed cell foam sheet material having a density of between 4 lbs./ft.³ and 6 lbs./ft.³. The box defines a cavity therein. A first planar member includes a 4 inch thick cross-linked polyethylene closed cell foam sheet material having a density of between 4 lbs./ft.³ and 6 lbs./ft.³. The first planar member is disposed within the cavity and affixed to four of the six sides of the outer box. A second planar member includes a 4 inch thick cross-linked polyethylene closed cell foam sheet material having a density of between 4 lbs./ft.³ and 6 lbs./ft.³. The second planar member is disposed within the cavity and is transverse to the first planar member. The second planar member is affixed to four of the six sides of the outer box, but is not affixed to two of the six sides to which the first planar member is affixed.

In yet another aspect, the invention is a method of making a plyometric jump box, in which a first pair of foam sides is formed in which each side has a first side height and a first side width, the first side width not being equal to the first side height and in which each of the first pair of foam sides includes a 4 inch thick cross-linked polyethylene closed cell foam sheet material having a density of between 4 lbs./ft.³ and 6 lbs./ft.³. A second pair of foam sides is formed in which each side has a second side height and a second side length. The second height is not equal to the second side length and the second side height is equal to the first side height. Each of the second pair of foam sides includes a 4 inch thick cross-linked polyethylene closed cell foam sheet material having a density of between 4 lbs./ft.³ and 6 lbs./ft.³. A third pair of foam sides is formed in which each side has a third side length and a third side width. The third side length is not equal to the third side width. The third side width is equal to the first side width. Each of the third pair of foam sides includes a 4 inch thick cross-linked polyethylene closed cell foam sheet material having a density of between 4 lbs./ft.³ and 6 lbs./ft.³. The first pair of foam sides is affixed to the second pair of foam sides and to the third pair of foam sides. The second pair of foam sides is affixed to the third pair of foam sides so as to form a box that defines a cavity therein. Each of the first pair of foam sides is disposed oppositely of each other and each of the second pair of foam sides is disposed oppositely of each other. Each of the third pair of foam sides is disposed oppositely of each other. A support structure is disposed inside of the cavity and is affixed the support structure to each of the sides so as to provide support to each of the sides.

These and other aspects of the invention will become apparent from the following description of the preferred embodiments taken in conjunction with the following drawings. As would be obvious to one skilled in the art, many variations and modifications of the invention may be effected without departing from the spirit and scope of the novel concepts of the disclosure.

BRIEF DESCRIPTION OF THE FIGURES OF THE DRAWINGS

FIG. 1 is a perspective view of one embodiment of a plyometric jump box.

FIG. 2 is an exploded view of the embodiment shown in FIG. 1.

FIG. 3A is a cross-sectional view of the embodiment show in FIG. 2, taken along line 3A-3A.

FIG. 3B is a cross-sectional view of the embodiment show in FIG. 3A, taken along line 3B-3B.

FIG. 3C is a cross-sectional view of the embodiment show in FIG. 3A, taken along line 3C-3C.

FIG. 4 is a schematic diagram of the embodiment shown in FIG. 1 in use.

DETAILED DESCRIPTION OF THE INVENTION

A preferred embodiment of the invention is now described in detail. Referring to the drawings, like numbers indicate like parts throughout the views. Unless otherwise specifically indicated in the disclosure that follows, the drawings are not necessarily drawn to scale. As used in the description herein and throughout the claims, the following terms take the meanings explicitly associated herein, unless the context clearly dictates otherwise: the meaning of “a,” “an,” and “the” includes plural reference, the meaning of “in” includes “in” and “on.” Also, as used herein, “lbs./ft.³” means pounds per cubic foot.

As shown in FIGS. 1, 2 and 3A-3B, one embodiment of a plyometric jump box 100 includes six sides organized in pairs, including a first side 110 and an opposite second side 118, a third side 112 and an opposite forth side 120, and a fifth side 114 and an opposite sixth side 116. Each side can include a 4 inch thick cross-linked polyethylene closed cell foam sheet material having a density of between 4 lbs./ft.³ and 6 lbs./ft.³ (which is available, for example, from Worldwide Foam, Elkhart, Ind., 620 Riverview Ave., Elkhart, Ind. 46516). The foam sheet material can include a peel-and-stick adhesive on one side. The sides are held together by the adhesive so that the jump box 100 defines a cavity 122 therein. In one embodiment, the adhesive is a pressure sensitive acrylic adhesive, which tends to resist softening as a result of being exposed to elevated temperatures. The foam used tends to be slow burning, chemically inert, slip resistant and durable through repeated use.

A support structure 124 is disposed in the cavity 122 to provide support for the sides and can be assembled during the assembly of the jump box 100. In one embodiment, the support structure 124 includes a first planar member 126 and a second planar member 128 (which can be divided into two parts, each disposed on an opposite side of the first planar member 126) that is transverse to the first planar member 126. The first planar member 126 is affixed to the first side 110, the second side 118, the fifth side 114 and the sixth side 116. The second planar member 128 is affixed to the first side 110, the second side 118, the third side 112 and the forth side 120. The support structure 124 can also include a 4 inch thick cross-linked polyethylene closed cell foam sheet material having a density of between 4 lbs./ft.³ and 6 lbs./ft.³. The support structure 124 provides support to the sides and prevents bowing when the jump box 100 is being jumped upon, especially when the jumper lands near the center. It has been found that a jump box 100 of this embodiment having the dimensions of 24″×20″×30″ can handle jumper of 250 lbs. without wobbling, slipping or rolling. While a foam support structure is used in one embodiment, other types of support structures (e.g., support structures made from wood, plastic, metal, etc.) may be employed without departing from the scope of the invention.

Gripping members can be disposed on at least two opposing sides of the jump box 100 and are used to facilitate picking up the jump box 100. In one embodiment the gripping member can be two holes 130 defined by opposing sides (e.g., sides 112 and 120 or sides 114 and 116, or both). The holes 130 should have dimensions that are smaller than a typical heel size so as to prevent a jumper's foot from passing therein when the jumper jumps on the jump box 100.

In one embodiment, the jump box 100 has the following dimensions: 24″×20″×30″. Other dimensions can be used in other embodiments, depending upon the height and ability of the target user. In one embodiment, the jump box 100 can have three different jump heights, depending on which side is placed on the floor. Also, boxes with several different dimensional schemes can be stacked to provide a specific desired jumping height. For example, two 24″×20″×30″ jump boxes can be stacked to give a range of jump heights of between 40″ and 60″.

In one method of making a jump box 100, the sides and the planar members are cut from sheet foam. The sides can be cut using conventional cutting methods, such as using a water jet cutter. The protective film is peeled off from the adhesive side of the foam and the parts are pressed together as shown.

In use, the jump box 100 is placed on a suitable surface 10 (e.g., a gym floor) and the jumper 12 jumps up onto the jump box 100. Since the foam is resilient, the likelihood of injury resulting from a missed jump is substantially reduced. Because the foam is stable and tends not to slip on most surfaces, the jump box 100 can be used on many different floor types.

The above described embodiments, while including the preferred embodiment and the best mode of the invention known to the inventor at the time of filing, are given as illustrative examples only. It will be readily appreciated that many deviations may be made from the specific embodiments disclosed in this specification without departing from the spirit and scope of the invention. Accordingly, the scope of the invention is to be determined by the claims below rather than being limited to the specifically described embodiments above. 

What is claimed is:
 1. A plyometric jump box, comprising: (a) a foam outer box having six sides, each side including a 4 inch thick cross-linked polyethylene closed cell foam sheet material having a density of between 4 lbs./ft.³ and 6 lbs./ft.³, the box defining a cavity therein; and (b) a support structure disposed inside of the cavity and coupled to each of the sides so as to provide support to each of the sides.
 2. The plyometric jump box of claim 1, wherein the support structure comprises: (a) a first planar member that includes a 4 inch thick cross-linked polyethylene closed cell foam sheet material having a density of between 4 lbs./ft.³ and 6 lbs./ft.³; and (b) a second planar member that includes a 4 inch thick cross-linked polyethylene closed cell foam sheet material having a density of between 4 lbs./ft.³ and 6 lbs./ft.³, the second planar member being transverse to the first planar member.
 3. The plyometric jump box of claim 1, wherein at least two opposing sides of the six sides include a gripping member.
 4. The plyometric jump box of claim 3, wherein at least one gripping member comprises a hole defined by one of the sides and passing therethrough.
 5. The plyometric jump box of claim 4, wherein the hole has dimensions that are configured to prevent a user's foot from passing therein.
 6. The plyometric jump box of claim 1, wherein in the six sides comprise: (a) a first pair of oppositely disposed sides in which each side has a first side height and a first side width, the first side width not being equal to the first side height; (b) a second pair of oppositely disposed sides in which each side has a second side height and a second side length, the second height not being equal to the second side length, the second side height being equal to the first side height; and (c) a third pair of oppositely disposed sides in which each side has a third side length and a third side width, the third side length not being equal to the third side width, the third side width being equal to the first side width, whereby the plyometric jump box provides three different jump heights depending on which of the six sides is placed down.
 7. A jump box, comprising: (a) a foam outer box having six sides, each side including a 4 inch thick cross-linked polyethylene closed cell foam sheet material having a density of between 4 lbs./ft.³ and 6 lbs./ft.³, the box defining a cavity therein; (b) a first planar member that includes a 4 inch thick cross-linked polyethylene closed cell foam sheet material having a density of between 4 lbs./ft.³ and 6 lbs./ft.³, the first planar member disposed within the cavity and affixed to four of the six sides of the outer box; and (c) a second planar member that includes a 4 inch thick cross-linked polyethylene closed cell foam sheet material having a density of between 4 lbs./ft.³ and 6 lbs./ft.³, the second planar member disposed within the cavity and being transverse to the first planar member, the second planar member affixed to four of the six sides of the outer box, but not affixed to two of the six sides to which the first planar member is affixed.
 8. The jump box of claim 7, wherein at least two opposing sides of the six sides include a gripping member.
 9. The jump box of claim 8, wherein at least one gripping member comprises a hole defined by one of the sides and passing therethrough.
 10. The jump box of claim 9, wherein the hole has dimensions that are configured to prevent a user's foot from passing therein.
 11. The jump box of claim 7, wherein in the six sides comprise: (a) a first pair of oppositely disposed sides in which each side has a first side height and a first side width, the first side width not being equal to the first side height; (b) a second pair of oppositely disposed sides in which each side has a second side height and a second side length, the second height not being equal to the second side length, the second side height being equal to the first side height; and (c) a third pair of oppositely disposed sides in which each side has a third side length and a third side width, the third side length not being equal to the third side width, the third side width being equal to the first side width, whereby the plyometric jump box provides three different jump heights depending on which of the six sides is placed down.
 12. A method of making a plyometric jump box, comprising the steps of: (a) forming a first pair of foam sides in which each side has a first side height and a first side width, the first side width not being equal to the first side height and in which each of the first pair of foam sides includes a 4 inch thick cross-linked polyethylene closed cell foam sheet material having a density of between 4 lbs./ft.³ and 6 lbs./ft.³; (b) forming a second pair of foam sides in which each side has a second side height and a second side length, the second height not being equal to the second side length, the second side height being equal to the first side height and in which each of the second pair of foam sides includes a 4 inch thick cross-linked polyethylene closed cell foam sheet material having a density of between 4 lbs./ft.³ and 6 lbs./ft.³; (c) forming a third pair of foam sides in which each side has a third side length and a third side width, the third side length not being equal to the third side width, the third side width being equal to the first side width and in which each of the third pair of foam sides includes a 4 inch thick cross-linked polyethylene closed cell foam sheet material having a density of between 4 lbs./ft.³ and 6 lbs./ft.³; (d) affixing the first pair of foam sides to the second pair of foam sides and to the third pair of foam sides and affixing the second pair of foam sides to the third pair of foam sides so as to form a box that defines a cavity therein, wherein each of the first pair of foam sides is disposed oppositely of each other and wherein each of the second pair of foam sides is disposed oppositely of each other and wherein each of the third pair of foam sides is disposed oppositely of each other; and (e) disposing a support structure inside of the cavity and affixing the support structure to each of the sides so as to provide support to each of the sides.
 13. The method of claim 12, wherein the affixing step is accomplished using an adhesive.
 14. The method of claim 13, wherein the adhesive comprises an acrylic adhesive.
 15. The method of claim 12, step of disposing a support structure comprises the steps of: (a) affixing a first planar member that includes a 4 inch thick cross-linked polyethylene closed cell foam sheet material having a density of between 4 lbs./ft.³ and 6 lbs./ft.³ to a a second planar member that includes a 4 inch thick cross-linked polyethylene closed cell foam sheet material having a density of between 4 lbs./ft.³ and 6 lbs./ft.³, the second planar member being transverse to the first planar member, thereby generating the support structure; (b) affixing the support structure to the first pair of foam sides, the second pair of foam sides and the third pair of foam sides.
 16. The method of claim 12, further comprising the step of forming a gripping member on at least two opposing foam sides of the box.
 17. The method of claim 16, wherein the step of forming a gripping member comprises defining a hole so as to pass through the at least two sides.
 18. The method of claim 17, wherein the step of defining a hole comprises cutting a hole that has dimensions that are configured to prevent a user's foot from passing therein. 